KR100271314B1 - Device and method to excavate automatically in an excavator - Google Patents

Abstract

PURPOSE: A device and a method to excavate automatically in an excavator are provided to be capable of assuring a reliable control though external conditions or loads are varied since a purge control is performed while making control rules determinable by the experience of a driver and a trial and error method. CONSTITUTION: A boom cylinder(134), an arm cylinder(135) and a bucket cylinder(136) respectively drive a boom, an arm and a bucket. A boom control valve(131), an arm control valve(132) and a bucket control valve(133) respectively adjust the amount of press oil provided to respective cylinders(134,135,136) to control the rotating angle of respective cylinders. A position sensor(121) senses the current rotating angle of the boom. An angle sensor(122) senses the current rotating angle of the arm. A stroke sensor(123) senses the current rotating angle of the bucket. A purge logic controller(110) receives the current rotating angles sensed by the sensors(121,122,123) to apply a purge logic control theory, and then outputs control signals to respective control valves(131,132,133).

Description

Automatic Excavator and Method of Excavator

The present invention is to automatically apply various operations using an excavator by applying the fuzzy control theory.

In general, excavators are each working machine (boom, arm, bucket), the boom cylinder, arm cylinder, bucket cylinder and the swinging motor for turning operation of the excavator body for driving the respective working machine, the hydraulic oil is a power source for each cylinder Consists of a prime mover and a hydraulic pump for supplying the oil, it is a hydraulic construction machine that performs a variety of operations, such as excavation, excavation, stop work.

In order to perform the stop operation by using the excavator, the boom, arm, and bucket must be controlled at the same time, and the bucket or arm tip must be controlled to move in a constant trajectory.

As described above, in order to perform various operations with an excavator, the operation lever of each work machine must be operated simultaneously by skilled operation according to each operation. Therefore, highly skilled operation is required, and thus an automatic excavation can be easily performed even by an inexperienced person. Many measures for the device have been proposed.

As one of the devices, a device has been proposed in which the boom and the bucket are simultaneously controlled even if the driver operates only the arm lever. That is, it controls to excavate at a predetermined angle while converging at an initially selected angle by controlling the flow rate provided to the boom cylinder and the bucket cylinder in consideration of the amount of movement of the arm tip by the operation of the arm lever to perform a straight or front excavation operation. That's how.

However, even when such a method is applied, when the tip of the arm is insufficiently deviated from the predetermined trajectory due to the inadequate driver's skill, it is impossible to maintain the initial constant angle by controlling the boom and the bucket. A problem arises in which the desired purpose cannot be achieved.

In order to solve the above problems, the Republic of Korea Patent Publication No. 96-13596 'Automatic work control device for construction machinery' has been proposed a control device applied to the variable structual control theory (Variable structual control). In other words, if the operator initially selects a work mode such as straight excavation, surface excavation, picking operation, constant angle excavation, selects the excavation angle in the corresponding operation, and then selects automatic operation, the operation automation controller automatically performs initial excavation. The flow rate supplied to each machine cylinder by calculating a control path to each machine control valve so that each machine moves along the optimal path calculated by the controller while calculating the optimum work path to maintain the angle while maintaining the angle. By controlling this, the work is performed while each work machine maintains the target digging angle. In addition, when the driver operates the automatic work speed control lever when the driver intends to increase the work speed during the automatic excavation work in the calculated work path, the work speed is increased in proportion to the manipulation amount.

In the excavator control apparatus to which the variable structure control theory described above is applied, PID (proportional-integral-derivative) control is used to control the nonlinear characteristics of the hydraulic valve and the servovalve.

However, even when the above PID control is used, there is a problem in that the height and the moving speed of each work machine cannot be kept constant when an impact is applied to the hydraulic circuit. In addition, the control device of the excavator to which the conventional variable structure control theory is applied has a problem in that it is not reliable in nonlinear control such as chattering phenomenon and arrival time delay according to external environment or load fluctuation.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, an excavator that can make a control rule that can be judged by the driver's experience, trial and error, etc. by fuzzy inference and predict and control the uncertainty. The purpose of the present invention is to provide an automatic digging device and method.

Excavation device of the present invention for achieving the above object, the boom, the arm and the bucket, which is a working machine, the boom cylinder, arm cylinder and bucket cylinder for driving the respective working machine, the amount of hydraulic oil provided to each cylinder Boom control valve, arm control valve and bucket control valve for adjusting the rotation angle of the cylinder by adjusting the rotation angle detection means for detecting the current rotation angle of the boom, arm and bucket, the rotation angle detection means In the excavator device of the excavator comprising a fuzzy logic controller for receiving the current rotation angle of the boom, the arm and the bucket to apply the fuzzy logic control theory, and outputs a control signal to each control valve, the fuzzy logic controller, A fuzzy input unit configured to receive a rotation angle signal of the boom, arm, and bucket from the rotation angle detection unit, convert the signal into a digital signal, and then convert the fuzzy parameter into a digital signal; A database unit storing predetermined fuzzy control rules for determining changes in the manipulated variable depending on whether the first difference between the difference and the control deviation and the second difference between the control deviation are positive or negative, and input from the fuzzy input unit Calculates the control deviation of the current (K), the first difference of the control deviation, and the second difference of the control deviation by calculating the variable values of the boom, the arm and the bucket, and the fuzzy control stored in the database unit by fuzzy inference. The boom control valve, the arm control valve and the bucket control by converting the operation amount output from the fuzzy inference unit and the amount of current for driving the boom, the arm and the bucket to determine a command by applying rules It is characterized by including the depurification output part which outputs to a valve, respectively.

In addition, the excavation method of the excavator according to the present invention, the initialization process for moving the boom, arm and bucket to the initial position, and the current (K) rotation angle of the boom, arm, and bucket when the operation mode of the excavator is automatic mode process, and the boom, the arm, and the current (K) rotation the set value compared to the control deviation value first order difference value (N _K) and control variation (△ N _K) of the bucket to detect, and the second order Calculating the difference value Δ ² N _K , the calculated first and second difference values ΔN _K , and the second difference value Δ ² N _K of the control deviation value N _K and the control deviation. According to Rule 1; ΔC _K = P _Cl , rule 2 if N _K = P ₁ ; ΔC _K = N _cl , rule 3 if N _K = N ₁ ; ΔC _K = P _c2 , rule 4 if ΔN _K = P ₂ ; If ΔN _K = N _2, ΔC _K = N _{c 2} , rule 5; ΔC _K = P _c3 , Rule 6 if Δ ² N _K = P ₃ ; △ ² N _K = N ₃ is △ C _K = N manipulated variables by applying the fuzzy control rules are defined as _C3 (△ C _K) fuzzy reasoning and the fuzzy inference result of the obtained operation amount boom, the arm, and the bucket to determine the The process of converting the current value to be applied to the control valve of the operation, and the task automation controller automatically calculates the optimal work path to perform the excavation work while maintaining the initial excavation angle and follow the optimal path calculated by the controller And outputting the current value to a control valve of the boom, the arm, and the bucket so that the boom, the arm, and the bucket move.

1 is a block diagram showing the configuration of an automatic excavator of an excavator according to the present invention.

2 is a flow chart showing the flow of the automatic digging method of the excavator according to the present invention.

* Explanation of symbols for main parts of the drawings

11O: Fuzzy Logic Controller 111: A / D Converter

112: fuzzy input unit 113: database unit

114: fuzzy inference unit 115: self-diagnostic unit

116: Diffuser output unit 117: D / A converter

121: position sensor 122: angle sensor

123: stroke sensor 131: boom control valve

132: arm control valve 133: bucket control valve

134: boom cylinder 135: arm cylinder

136: bucket cylinder

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing an automatic excavator of an excavator according to the present invention, a boom, an arm and a bucket (not shown), which is a working machine, a boom cylinder 134, an arm cylinder 135 for driving the respective working machines and A boom control valve 131, an arm control valve 132, and a bucket control valve 133 for adjusting the rotation angle of each cylinder by adjusting the bucket cylinder 136 and the amount of pressure oil provided to the cylinders 134, 135, and 136. ), A position sensor 121 for detecting a current rotation angle of the boom, an angle sensor 122 for detecting a current rotation angle of the arm, a stroke sensor 123 for detecting a current rotation angle of the bucket, and After receiving the current rotation angle of the boom, arm, and bucket detected through the position sensor 121, the angle sensor 122, and the stroke sensor 123, and applying fuzzy logic control theory, the control valves 131, 132, and 133 are applied. Fuzzy logic controller 110 for outputting a control signal to the It is.

The fuzzy logic controller 110 may include an A / D converter 111 for converting a sensing signal input from the position sensor 121, the angle sensor 122, and the stroke sensor 123 into a digital signal, and the digital signal. In order to apply the converted sensing signal to the fuzzy control program, a fuzzy input unit 112 for performing proper signal processing, a database unit 113 storing a plurality of fuzzy control rules, and stored in the database unit 113 In the fuzzy inference unit 114 performing fuzzy inference based on the fuzzy control rule, the self diagnosis unit 115 for self-diagnosing the inference process of the fuzzy inference unit 114, and the fuzzy inference unit 114 The depurifier output unit 116 for signal-processing the output fuzzy inference result as the amount of current, and converts the signal output from the depurifier output unit 116 into an analog signal and outputs the analog signal to each control valve (131, 132, 133) Is configured comprising a D / A converter 117 such that the amount of current that is applied to the variable valve.

Hereinafter, the operation and effect of the present invention will be described with reference to the block diagram of FIG. 1 and the flowchart of FIG. 2.

First, look at the fuzzy control rules stored in the database unit 113 as follows.

Rule 1; if N _K = P ₁ △ C _K = P _C1

Rule (rule) 2; if _{N K = N 1 △ C K} = N C1

Rule 3; when △ N _K = P ₂ △ C _K = P _C2

Rule _{(rule) 4; △ N K} = N 2 = N _K If the △ C _C2

Rule 5; if △ ² N _K = P ₃ △ C _K = P _C3

Rule 6; if △ ² N _K = N ₃ △ C _K = N _C3

Here, with respect to time K, N _K is the control deviation value (N _K = ν-μ _K ), and Δ N _K is the first difference of the control deviation (Δ N _K = N _K -N _K-1 ). , Δ ² N _K is the second difference (Δ ² N _K = Δ N _K − Δ N _K-1 ) of the control deviation. Δ C _K means a change of the manipulated variable (Δ C _K = C _K − C _{K −1} ) as a command. In addition, P is an abbreviation of positive and N is a negative abbreviation. Further, ν and μ _K mean the speeds of the set speed (target speed) and the current K, respectively.

The fuzzy inference unit 114 determines the amount of operation by fuzzy inference based on the above fuzzy control rule.

In order to work with an excavator, an initialization work in which each work machine moves to an initial position must be performed first (step 21). That is, the boom, arm and bucket move to the initial position (step 22). In step 23, if the excavator operation is set to automatic mode, the process proceeds to the next step, step 24. If not, the control flow is terminated and the manual mode operation is performed by the operator.

Step 24 is a step of sensing the current rotation angle of the boom, the arm and the bucket bar, the current rotation angle of the boom, arm and bucket through the position sensor 121, the angle sensor 122 and the stroke sensor 123 do.

Step 25 is a signal processing of the input sensing signal, which is performed by the A / D converter 111 and the fuzzy input unit 112. That is, the A / D converter 111 converts the sensing signal into a digital signal, and the fuzzy input unit 112 performs appropriate signal processing so that the sensing signal can be applied to a fuzzy control program.

Step 26 is a step in which the fuzzy inference unit 114 performs fuzzy inference based on the fuzzy control rules stored in the database unit 113, and the first difference and the second difference between the control deviation value and the control deviation. MV is determined by applying to each fuzzy control rule. As an example, if rule 1 is applied, if the control deviation value is positive, that is, if the current rotation angle is greater than the target rotation angle, the change amount of the manipulation amount is made negative by lowering the current manipulation amount.

As described above, the fuzzy inference result output from the fuzzy inference unit 114 corrects an error by executing a fuzzy logic, which determines an error correction amount based on a current error amount and a change amount of the error.

Table 1 below shows the control rules for fuzzy logic.

TABLE 1

In Table 1, the vertical side indicates the current error amount, and the horizontal side indicates the amount of change in the error. Here, the meaning of the fuzzy language value is shown in Table 2 below.

TABLE 2

The fuzzy inference result of which the error is corrected by the fuzzy logic of Table 2 is converted into a current value at the depurifying output unit 116 (step 28), and is converted into an analog signal at the D / A converter 117 and then the boom control valve. 131, the arm control valve 132 and the bucket control valve 133 are input (step 29). At this time, the hydraulic pressure supplied to each cylinder (134, 135, 136) from the hydraulic pump (not shown) is varied according to the current value applied to each of the control valves (131, 132, 133), the boom cylinder 134, arm cylinder 135 and As the operation amount of the bucket cylinder 136 is variable, the current rotation angle of the boom, the arm and the bucket is changed.

And the current rotation angle of the boom, arm and bucket is detected by the position sensor 121, the angle sensor 122 and the stroke sensor 123, as described above, the position sensor 121, the angle sensor 122 and The stroke sensor 123 outputs a sensing signal, and the sensing signal is inputted to the fuzzy logic controller 110 and purged, and then input to the control valves 131, 132, and 133.

As described above, according to the present invention, fuzzy control is made by fuzzy reasoning of control rules which can be judged by the driver's experience and trial and error, so that reliable control can be performed even when the external environment or load of the excavator is changed. It has an effect.

Claims (3)

(Correction) Adjusting the rotation angle of each cylinder by adjusting the boom, the arm and the bucket, which is a working machine, the boom cylinder, the arm cylinder and the bucket cylinder for driving the respective working machine, and the amount of pressure oil provided to each cylinder Input boom control valve, arm control valve and bucket control valve, the rotation angle detection means for detecting the current rotation angle of the boom, arm and bucket, the current rotation angle of the boom, arm and bucket detected by the rotation angle detection means And a fuzzy logic controller for outputting a control signal to each of the control valves after the fuzzy logic control theory is applied. The fuzzy logic controller includes a boom, an arm, and a bucket from the rotation angle sensing means. A fuzzy input unit that receives the rotation angle signal of the controller and converts it into a digital signal, and then converts it into a fuzzy variable, a first difference value between the control deviation and the control deviation, and a second difference between the control deviation A database unit in which a predetermined fuzzy control rule for determining a change in the manipulated variable is determined according to whether the value is positive or negative, and the variable values of the boom, the arm and the bucket inputted from the fuzzy input unit are calculated and present (K). A fuzzy inference unit for determining a command amount by applying the fuzzy control rules stored in the database unit by fuzzy inference after obtaining a control deviation, a first difference value of the control deviation, and a second difference value of the control deviation; And an extruding output unit configured to convert an operation amount output from the purge inference unit into an amount of current for driving the boom, the arm, and the bucket and output the output to the boom control valve, the arm control valve, and the bucket control valve, respectively. Automatic excavation device. The apparatus of claim 1, wherein the fuzzy logic controller further comprises a self-diagnostic unit configured to self-diagnose the inference process of the fuzzy inference unit. (Correction) the initialization process of moving the boom, the arm and the bucket to the initial position, the process of detecting the current (K) rotation angle of the boom, arm, and bucket when the operation mode of the excavator is automatic mode, the boom, Comparing the current (K) rotation angle of the arm and the bucket with a set value to obtain a control deviation value (NK), a first difference value (ΔNK), and a second difference value (Δ2NK) of the control deviation; Rule 1 according to the calculated control deviation value NK, the first difference value ΔNK of the control deviation, and the second difference value Δ2NK; CK = PC1, rule 2 if NK = P1; CK = NC1, rule 3 if NK = N1; ΔNK = P2, ΔCK = PC2, rule 4; ΔCK = NC2, rule 5 if ΔNK = N2; ΔCK = PC3, rule 6 if DELTA 2NK = P3; When Δ2NK = N3, the fuzzy inference process of determining the manipulated value ΔCK by applying the fuzzy control rules defined as ΔCK = NC3, and applying the manipulated value obtained as a result of the fuzzy inference to the control valve of the boom, arm, and bucket Process of converting the current to the current value, and the task automation controller automatically calculates the optimum work path for the excavation work while maintaining the initial excavation angle, and follows the optimal path calculated by the controller for the boom, arm, and bucket. And a step of outputting the current value to a control valve of the boom, the arm, and the bucket so as to move the excavator.

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